Just on Saturday we got to listen to a number of ML-TLs with FR & WR125s.

A GM ML-TL (driver down 14"), 3 variations on the bipole i designed based on Tim Formans WR TMM, and a shorter Tim Forman bi-pole.

If you are going to port the FR or WR125 (and not make them aperiodic) i suggest a high pass filter to keep any signal from getting to them in the area where they are unloaded -- otherwise they will "fart" when that signal causes them to bottom out.

Our feeling after the event is that one should avoid tuning these too low (ie the GM pipes are going under the saw to become shorter, and the tuning will be raised.

Has anyone tried a WR125ST (16-ohm) as the rear driver in a bipole? I'm thinking it might give some of the benefits of a bipole and lessen the bipole effect (not as focused as a front-firing system?).

I just took delivery of a pair of FR125S's yesterday and plopped them in my RAW-1F in place of the WR125S's. Wow! Quite the improvement. I also played around with my Marchand XM44 crossover for the first time in comparison to no crossover (FR125 running full range in a 7L aperiodic cab, with dual subs at 100HZ). In the past I've only compared the Marchand to passive crossovers, and it always won easily. But compared to no crossover, it's clearly compromising my Meitner amps. So I've suddenly become highly interested in this bipole idea.

Originally posted by audiobomber
Has anyone tried a WR125ST (16-ohm) as the rear driver in a bipole? I'm thinking it might give some of the benefits of a bipole and lessen the bipole effect (not as focused as a front-firing system?).

Bob suggested that really early on to me. I don't know that anyone has tried it yet. It should work to decrease the amount of baffle step compensation. One could go a step further and make a triangle (or pentangon or hexagon) shaped column and load 2 STs on the back.